1. Field
The present embodiments generally relate to methods for exothermal synthesis. More particularly, embodiments of the present invention relate to methods for synthesis of ammonia and other chemicals using one or more catalyst beds.
2. Description of the Related Art
Conventional exothermic chemical synthesis reactors feature an exothermal reaction chamber having catalyst beds contained in a catalyst containment basket or a “basket” that is disposed inside an outer pressure shell. The catalyst beds are contained in the basket so that the outer pressure shell is not directly exposed to the high temperatures inherent in the exothermic synthesis reaction. The outer pressure shell is typically cooled by flowing a reactor feed gas through an annular space formed between the outside of the basket and the inside of the outer pressure shell. The heat transferred to the feed gas from the exothermic reaction occurring in the basket preheats the feed gas to the required reaction temperature prior to the feed gas being passed to the catalyst beds. The preheated feed gas then passes to the catalyst beds directly or via an internal heat exchanger, where at least a portion of the flow is converted into a by-product such as ammonia or other known chemical compounds.
The heats and pressures generated by the exothermic synthesis in the annular space between the basket and the outer pressure shell are significant. The design of the basket must take into account the physical realities of the reaction within the catalyst beds by increasing the wall thicknesses of the basket and selecting other metallurgical parameters necessary for the baskets to survive the heat generated during the exothermal process. The design of the outer pressure shell must also take these physical realities into account since the outer shell is exposed to significant heat and pressure during, among other things, the pre-heating of the feed gas prior to introduction into the basket. The metallurgic requirements can drive significant costs into the design and construction of an exothermal reaction chamber. There is a need, therefore, to provide a new system and method that can reduce the metallurgic requirements of exothermal reaction chambers, including those reaction chambers used in the production of ammonia or other known chemicals.